Screen



Dec. 31, 1963 r w. E. BIXBY 3,116,239

SCREEN Filed Aug. 10, 1961 INVENTOR. WflLL/ICE E. BIA 8V HIS flTTOENEYS United States Patent F 3,116,239 SQREEN Wallace E. Bixhy, Wellington, Ohio, assignor to Wedge (g/lire Corporation, Wellington, Ohio, a corporation of Filed Aug. 10, 1961, Ser. No. 130,559 3 Claims. (til. 209-395) This invention relates to a screen assembly. More particularly, the invention relates to a marcelled screen suitable for use in dewatering operations carried out in the mining industry; however, the invention is not necessarily so limited.

A screen assembly of the type herein described typically comprises one or more screen sections mounted on a support, each section including a plurality of generally parallel metallic wire elements of narrow width and relatively great length supported by spaced parallel cross bars. The wires are spaced one from the other so as to permit the passage of liquids, dust and small particles of predetermined size through the screen. The individual screen sections may be of any suitable size, a common size being eight feet in length and approximately three feet in width. Often the support for the screen is a vibratory support which shakes the screen and thereby aids in the screening operation. These screens and uses to which they are put are well known in the art.

In operations involving screens of this type, a particular problem is encountered when the material passing over the screen includes slivers or platelets as Well as generally round or cubical particles. This problem arises from the fact that the earlier screens contained elongated linear slots between the generally parallel wire elements. Platelets or slivers of comparatively large area could pass freely through these slots and in most operations the passage of these comparatively large particles through the screen is objectionable.

In order to alleviate this problem, attempts have been made to form protuberances on the parallel wire elements at spaced intervals, which protuberances would provide localized obstructions in the slots between the wire elements to prevent the passage of oversized slivers or platelets through the screen. For reasons of economy and manufacture, the material forming the protuberances was forced out of the Wires in a forming operation. This type of screen was not favorably accepted in the trade for two principal reasons, one being that this type of construction reduces the open area in the screen and the other being that this type of construction is effective only in screens having a comparatively small slot width (one millimeter or less). For large slot widths, the protuberances, which were limited in size due to the fact that they were taken from the wire, had little effect on the passage of slivers or platelets through the screen. Within the limited range of opening sizes in which the protuberances were effective, the passage of platelets through the screens is generally of minor importance, the problem with platelets being most prominent where the screen opening size exceeds one millimeter.

On object of the present invention is to provide a new and improved screen so constructed and arranged that slivers or platelets of a large area will not pass through the screen.

Another object of the present invention is to provide a new and improved screen of the type described wherein the parallel wire elements which form the screen surface are sinuously curved or marcelled so as to restrict passage of large slivers or platelets through the screen without limiting the open area of the screen.

Other objects and advantages reside in the construction of parts, the combination thereof, and the mode of 3,116,239 Patented Dec. 31, 1963 ice operation, as will become more apparent from the following description.

In the drawing:

FIGURE 1 is a fragmentary exploded perspective view illustrating a partially formed wire element employed in the screen of the present invention.

FIGURE 2 is another fragmentary exploded perspective view illustrating a coining operation performed on the partially formed wire element of FIGURE 1.

FIGURE 3 is a fragmentary perspective view illustrating the wire element after coining according to FIGURE 2.

FIGURE 4 is a fragmentary plan view illustrating a portion of the screen of the present invention.

FIGURE 5 is a fragmentary sectional view taken substantially along the line 5-5 of FIGURE 4.

FIGURE 6 is a fragmentary sectional view taken substantially along the line 6-6 of FIGURE 4.

Referring to the drawing in greater detail, FIGURE 4 illustrates a portion of a screen 10 formed according to the present invention. This screen comprises a plurality of generally parallel wire elements 12 each of which is looped about spaced support rods 14. Only one of the support rods 14 is illustrated in FIGURE 4. These wire elements are secured in fixed relation by means of nuts 16 threadedly engaging the ends of the support rods 14.

It is to be understood that FIGURE 4 illustrates only a small portion of the screen which, as previously mentioned, may comprise a section eight feet in length and approximately three feet in width, the support rods 14 being spaced at approximate three-inch intervals along the length of the screen.

As clearly appears in FIGURE 4, each of the wire elements 12 is sinuously undulated in a direction transverse to its length. In the assembled screen, the undulations occupy substantially a common plane, the adjacent wire elements being nested together so as to form sinuous slots 18 therebetween. These slots 18 each have a substantially constant width throughout the distance between adjacent support rods 14.

In the manufacture of the present screen, it is found impractical to form sinuous undulations in the wire elements 12 prior to the time these wire elements are looped for engagement with the support rods 14. Thus, existing machinery for looping the wire elements requires straight wire elements of uniform cross section. It is therefore advantageous in the formation of the present screen to first loop the wire and then produce the sinuous undulations in the wire. The method for forming the wire elements 12 is illustrated in FIGURES 1 and 2.

FIGURE 1 illustrates a length of Wire 12a of circular cross section which has been looped at spaced intervals to form loops 2t) therein, these loops being substantially coplanar. Methods and apparatus for looping the wire element 12a are well established in the art and form no part of the present invention. Ordinarily, spindles 22, as shown in FIGURE 1, engage the loops 20 to maintain a fixed spacing between these loops.

After the Wire 12a has been looped, it is passed between a pair of coining dies 24, 26 as shown in FIGURE 2. The die 26 is provided with spindles 28 which replace the spindles 22 of the looping machine. The die 24 is provided with apertures 30 to receive the spindles 28, thus enabling the dies to move into close operative relationship.

Disposed between the apertures 30 and the die 24 are a plurality of coining punches 32 having generally trapezoidal working faces and arranged in a linear array. The spaces 34 between the coining punches are recessed away from the work-rig faces of the coining punches to receive metal displaced from the wire elements during the coining operation as will be more fully described subsequently. At the working face, each coining punch 32 slopes inwardly of the die 24 as it moves upwardly, establishing a shoulder 33 overlying the coining punches. The die 26 has a similar array of coining punches adapted to fi-t under the shoulder 33 as the dies 24, 26 coact. In the die 26, the coining punches have a shape similar to that of the coining punches 32 but are staggered relative to the coining punches 32 such that the coining punches in the die 26 are directly opposite the recesses 34 in the die 24.

FIGURE 3 illustrates a wire element 12 formed by compressing the wire element 12a between the coining dies 24, 26. As can be observed, indentations or flats 38 along the sides thereof formed by the coining punches in the coining dies, the indentations on one side of the wire element being staggered relative to the indentations on the other side of the wire element.

Between the indentations on each side of the wire element are protuberances 40 produced by the displacement of material from the wire elements into the recesses 34 of the coining dies.

Due to the aforementioned slope in the working faces of the coining punches 32 in each of the dies 24, 26, the opposing working faces diverge from bottom to top. Thus, when the die-s 24, .26 coact, the wire element 12a is wedged upwardly by the working faces of the coining on the upper and lower surfaces, respectively, of the wire element represent surface portions of the original Wire element 120 which were not directly engaged by portions of the coining dies.

Surrounding each aperture 30 in the die 24 and each spindle 28 in the die 26 is an annular recess 36 which permits the dies to coact without exerting pressure on the lower portions of the loops 20 formed in the wire element. However, at the upper portion of the loop where the wire crosses itself, the wire is of double thickness and this port-ion is compressed between the die elements 24 and 26 to form flattened surfaces 46 at the tops of the loops. When the wire elements 12 are assembled side by side as illustrated in FIGURE 4, the spacing between these wire elements is determined by the extent to which the wire elements have been compressed at the point of cross-over in the loops. It will be understood, of course, that the thickness of the wire element at the point of crossover in the separation is desired, washers or shims can be used to increase the separation as is well known in the art.

FIGURE illustrates the cross sectional shape of the wire elements at the point where a protuberance 40 has been formed in a recess 34 of one of the coining dies. Due to the slope of the working face of the coining punch on one die, and due to a complementary slope in the recess 34 on the opposite die, the coined wire element has a to bottom, as shown in FIG- FIGURE 6 illustrates the cross section at a point intermediate the protuberances 40 where both sides of the wire elements have been acted only by the working face of a coining punch. Here again, since the coining punches are sloped in a complementary manner, the wire element 4; through the slots are held at the top of the screen where they can be carried off the screen by the flow of material passing thereover.

From the foregoing description, it will be apparent that the method disclosed provides a means for forming a sinuously undulated wire element after loops have been formed in the wire element and without damage to the loops. As clearly appears in FIGURE 4, the wire elements formed with t e method of the present invention cooperate to produce a uniform slot dimension in 21 marcelled screen formed from the wire elements, the slot being sinuously undulated so as to minimize the passage of platelets or slivers through the screen.

In FIGURE 4 it will be noted that the undulatory crests in one wire element project partially between the undulatory crests of the adjacent wire element, thus precluding even the thinnest of slivers or platelets from passing through the screen if the overall length of the platelet exceeds one-half the undulatory wave length of the wire element. Due to this characteristic, it is also apparent that the spacing between wire elements can be increased with the aid of shims or washers so as to increase the slot width of the screen without materially increasing the probability that slivers or platelets will pass through the screen. A single set of coining dies may be used to produce wire elements capable of satisfying a comparatively wide range of slot widths.

It will occur to those skilled in the art that the character of the undulations in the wire elements 12 may be varied by adjusting the size of the coining punches 32 in the coining dies 24, 26. In the coining dies illustrated, the punches 32 have a width greater than the width of the recesses 34 therebetween. Thus, the punches 32 do not interdigitate. However, if the punches 32 are made narrower with a consequent increase in the spacing between the punches, it is possible to produce coining dies with punch elements which interdigitate thereby enhancing the undulating character of the wire elements. However, it is found that for screen requirements in most commercial installations, a slot width ranging from one to six millimeters is required and this range can be covered without interdigitating punch elements.

Although the preferred embodiment of the device and method of making same has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A screen assembly comprising a plurality of elongate wire elements each having a plurality of spaced generally coplanar loops therein, the portions of said wire elements intermediate said loops having spaced indentations in opposite sides thereof separated by outwardly directed protuberances, the indentations in one side being staggered relative to the indentations in the opposite side so as to impart a sinuous shape to said wire elements, and means engaging the loops in said wire elements to support said wire elements in parallel relation with the protuberances in one wire element positioned opposite the indentations in the adjacent wire element, the indentations and protuberances on opposite sides of each wire element being inclined oppositely, said wire elements cooperating to establish a generally planar screen surface having sinuous slots therein, said slots diverging in a direction transverse to the screen surface.

2. A device of the class described comprising a plurality of elongate wire elements each having a plurality of longitudinally spaced generally coplanar downwardly directed loops therein, the portions of said wire elements intermediate said loops having spaced longitudinally disposed flat surfaces on opposite sides thereof, the flat amazes surfaces on one side being staggered with respect to the flat surfaces on the other side, said flat surfaces being inclined with respect to the plane of said loops and the flat surfaces on the opposite sides of said intermediate portions converging in the downward direction, said intermediate portions having spaced protuberances staggered along the opposite sides thereof and disposed between said flat surfaces, the combination of flat surfaces and protuberances on opposite sides of said wire elements imparting a longitudinally sinuous shape thereto, and means engaging the loops in said wire elements to support the same in juxtaposed relation with the wire elements extending in generally parallel relation and with the protuberances in one wire element disposed opposite the flat surfaces in the wire elements on both sides thereof, adjacent wire elements cooperating to establish a generally planar screen surface having sinuous slots therein, said slots diverging in a direction transverse to the screen surface.

3. A device of the class described, comprising a plurality of elongate wire elements, said wire elements having spaced indentations in opposite sides thereof separated by outwardly directed protu erances, the indentations in one side being staggered relative to the indentations in the opposite side so as to impart a sinuous shape to said wire elements, and means engaging said wire elements to support said wire elements in parallel relation with the protuberances in one wire element positioned opposite the indentations in the adjacent wire element, the indentations and protuberances on opposite sides of each wire element being inclined oppositely, said wire elements cooperating to establish a generally planar screen surface having sinuous slots therein, said slots diverging in a direction transverse to the screen surface.

References Cited in the file of this patent UNETED STATES PATENTS 

3. A DEVICE OF THE CLASS DESCRIBED, COMPRISING A PLURALITY OF ELONGATAE WIRE ELEMENTS, AND WIRE ELEMENTS HAVING SPACED INDENTATIONS IN OPPOSITE SIDES THEREOF SEPARATED BY OUTWARDLY DIRECTED PROTUBERANCES, THE INDENTATIONS IN ONE SIDE BEING STAGGERED RELATIVE TO THE INDENTATIONS IN THE OPPOSITE SIDE SO AS TO IMPART A SINUOUS SHAPE TO SAID WIRE ELEMENTS, AND MEANS ENGAGING SAID WIRE ELEMENTS TO SUPPORT SAID WIRE ELEMENTS IN PARALLEL RELATION WITH THE PROTUBERANCES IN ONE WIRE ELEMENTS POSITIONED OPPOSITE THE INDENTATIONS IN THE ADJACENT WIRE ELEMENT, 